John Briffa: Teething troubles

Many of us put our trust in chemical fluoride as a safe and effective weapon in the fight against tooth decay. In parts of the UK, water supplies come with fluoride already added, and dentists here have recently called for this practice to be made more widespread. However, the British enthusiasm for fluoride is not shared in other parts of Europe. The Belgian government has recently outlawed the sale of fluoride tablets and chewing gum, and many European countries have said a flat no to the addition of fluoride to their water supplies.

Dental decay remains a relatively common problem. From a nutritional perspective, there is evidence that a diet low in sugar and refined starches, but rich in unprocessed plant matter, such as salad ingredients, helps to protect our teeth from decay. In addition to these tooth-friendly fundamentals, dentists extol the virtues of regular brushing and the use of fluoride, too.

While we have been adding fluoride to our water for the past 40 years, it is well recognised that the quality of the original studies into this practice left a lot to be desired. Recently, a large review of the scientific literature on water fluoridation was published in the British Medical Journal. The results of this research, commonly referred to as the York study, showed that the rationale for water fluoridation is based on weak scientific evidence. In addition, the study found that just one in six people drinking fluoridated water appears to benefit from this practice. Not only that, but almost half of individuals drinking fluoridated water at permissible levels exhibit a condition known as dental fluorosis - a mottling and discolouration of the teeth caused by fluoride toxicity. Some dentists question the wisdom of preventing dental disease in one in six people, only to cause it in one in two.

In Ireland, where 70 per cent of the water supply is fluoridated, there has been mounting opposition to the practice. Many parties are not just citing the lack of evidence of clear benefit, but also potential health risks posed by the unmonitored ingestion of a potentially toxic chemical. The recent Belgian ban on fluoride was based on fears that it might increase the risk of osteoporosis. Some have also raised issues about the ethics of water fluoridation, claiming that this is essentially mass medication without consent. It is sobering to note that the following European countries have rejected water fluoridation: Germany, Belgium, Sweden, Italy, Denmark, Holland and France.

Personally, I think there are real medical and ethical question marks over the practice of water fluoridation. Yet, in the face of these, the British Dental Association has urged the government to expand the proportion of people in the UK receiving fluoridated water from 10 to 25 per cent. My advice: don't swallow it.

Nutrition news

Although the medical profession can sometimes take a rather laissez-fair attitude to the importance of a good regular bowel habit, most people find they feel better when there are no hold-ups in that department.

For those experiencing some sluggishness of bowel, fruit is often recommended for its high fibre and fluid content. The concept of eating more fruit to help keep us regular makes good sense, but does it actually work?

In a recent study, a group of individuals eating a normal diet were fed with kiwi fruit each day for three weeks to see what effect this had on bowel habit.

The 'dose' of kiwi fruit was one piece of fruit for every 30kg (66lb or 5st) of body weight. Compared to those eating just a standard diet, individuals on the kiwi fruit therapy were found to have softer, bulkier and more frequent bowel motions.

This study shows that consuming a couple of kiwi fruit each day may be all it takes to help dissipate any bowel-related congestion.

Dear John

I am 31 and have been on the pill for five years. I suffer from depression and have read this might be due to the pill. Is this true? L Long, Gidea Park, Essex

While depression can be caused by many different factors, it is, as you suggest, a recognised side-effect of the pill. The pill is believed to deplete vitamin B6 in the body. Vitamin B6 has a number of health-giving properties, one of which is to participate in the reactions that generate 'feel-good' chemicals in the brain. In one study, half of the depressed women who took the pill had laboratory evidence of B6 deficiency. In practice, a B6 supplementation - 40mg a day - is generally effective in improving low mood related to oral contraceptive use.

Another nutrient that may be affected is magnesium. Statistically, women on the pill are significantly more likely to suffer from a deficiency of this nutrient compared to non-pill takers. Like vitamin B6, magnesium is involved in many body processes, including energy production and bone-building. It is also considered to have calming effects on the brain.

For these reasons, I suggest you also take a supplement of magnesium in addition to the B6. Take 250-350mg per day.

· If you have any issues you would like Dr John Briffa to address in this column, please contact him by email on john.briffa@observer.co.uk. Please note that Dr Briffa cannot enter into any personal correspondence.